U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Physical Measurement Laboratory / Sensor Science Division

Fluid Metrology Group

Tools and Instruments

Displaying 1 - 6 of 6
gas flow standards instrument

Gas Flow Standards

NIST uses pressure, volume, temperature, and time (PVTt) standards to calibrate gas flow meters. PVTt flow standards generate selected, steady gas flows through
Apparatus for calibrating hydrometers and measuring the density of liquids

Liquid Density

The Fluid Metrology Group developed a dual-purpose, automated apparatus to calibrate hydrometers via Cuckow’s method and to also measure the density of
15 L/s Dynamic Flow Standard

Liquid Flow Standards

The Fluid Metrology Group has four liquid flow standards spanning the flow range 0.002 L/s to 65 L/s with uncertainties less than 0.06 % at a 95 % confidence
transient gas flow instruments

Transient Gas Flow Facility

A compressor is used to pressurize up to twenty-five 40 L gas cylinders to 35 MPa. The cylinders can then be used as a source of rapidly changing gas flow by
wind tunnel instrument

Wind Tunnel

NIST’s wind tunnel can produce air speeds between 0.15 m/s and 40 m/s. The air speed reference is a Laser Doppler Anemometer (LDA) with an uncertainty of 2.5 %